The present invention relates to friction clutches in general, and more particularly to improvements in clutch plates for use in friction clutches, especially in friction clutches of automotive vehicles.
It is already known to assemble the clutch plate of a friction clutch of two subassemblies which are rotatable, within limits, relative to one another against the opposition of coil springs or analogous energy storing elements. For example, one of the subassemblies may comprise a hub which can be non-rotatably secured to the input shaft of a change-speed transmission in an automotive vehicle and is provided with two spaced-apart coaxial annular discs or cheeks. The other subassembly can comprise a carrier for one or more friction linings; such carrier can constitute a flat washer-like body whose radially innermost portion extends into the space between the cheeks on the hub of the one subassembly. The carrier is rotatable by the flywheel on the crankshaft of the internal combustion engine in the automotive vehicle, and the aforementioned coil springs are inserted into registering windows which are provided in the cheeks and in the carrier so that they can yield, to a certain extent, to permit some angular displacement of the carrier relative to the hub and/or vice versa.
It is further known to provide a friction clutch of the above outlined character with a friction generating unit which is interposed in the path of power flow between the hub and the carrier, and to assemble such friction generating unit from a friction generating component and an axially stressed resilient component which latter biases the friction generating component. Reference may be had, for example, to German Pat. No. 2,436,288, and particularly to FIG. 5 of this publication. The two components of the friction generating unit are disposed at the opposite sides of the carrier and are connected to each other by distancing elements in the form of rivets. Still further, the friction generating unit which is disclosed in the German publication employs friction pads and a dished spring which urges the friction pads axially. Such dished spring and the friction pads are interposed between the carrier on the one hand and the aforementioned components of the friction generating unit on the other hand. A drawback of the patented clutch plate is that it is rather bulky and expensive. Furthermore, the patented construction does not invariably prevent rattling of its parts and/or the generation of other forms of noise.